D. Kleinjan
A5079580350- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Quantum Chromodynamics and Particle Interactions
- Particle accelerators and beam dynamics
- Particle Accelerators and Free-Electron Lasers
- Dark Matter and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- Superconducting Materials and Applications
- Atomic and Molecular Physics
- Nuclear physics research studies
- Nuclear Physics and Applications
- Magnetic confinement fusion research
- Plasma Diagnostics and Applications
- Geophysics and Gravity Measurements
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced NMR Techniques and Applications
- Geomagnetism and Paleomagnetism Studies
- Neutrino Physics Research
- Stochastic processes and statistical mechanics
- Nuclear reactor physics and engineering
- Mass Spectrometry Techniques and Applications
- Particle Detector Development and Performance
- Distributed and Parallel Computing Systems
- Simulation Techniques and Applications
- Statistical Methods and Bayesian Inference
Los Alamos National Laboratory
2015-2024
Los Alamos Medical Center
2024
University of California, Riverside
2012-2023
Banaras Hindu University
2020-2023
Charles University
2020-2023
Bhabha Atomic Research Centre
2022-2023
Augustana University
2022-2023
PHENIX laboratory
2020-2022
University of Illinois Urbana-Champaign
2019
New Mexico State University
2014
Evidence for a flavor asymmetry between the $\overline{u}$ and $\overline{d}$ quark distributions in proton has been found deep-inelastic scattering Drell-Yan experiments. The pronounced dependence of this on $x$ (fraction nucleon momentum carried by partons) observed Fermilab E866 experiment suggested drop $\overline{d}(x)/\overline{u}(x)$ ratio $x>0.15$ region. We report results from SeaQuest E906 with improved statistical precision large region up to $x=0.45$ using 120 GeV beam. Two...
The SeaQuest spectrometer at Fermilab was designed to detect oppositely-charged pairs of muons (dimuons) produced by interactions between a 120 GeV proton beam and liquid hydrogen, deuterium solid nuclear targets. primary physics program uses the Drell-Yan process probe antiquark distributions in target nucleon. consists system, two dipole magnets four detector stations. upstream magnet is closed-aperture iron which also serves as dump, while second an open aperture magnet. Each stations...
The LANSCE accelerator is currently powered by a filament-driven, biased converter-type H- ion source that operates at 10%, the highest plasma duty factor for this type of source, using only ∼2.2 SCCM H2. needs to be replaced every 4 weeks, which takes up days. measured negative beam current 12-16 mA falls below desired 24 acceptance LANCSE accelerator. SNS (Spallation Neutron Source) RF-driven, injects ∼50 into 60 Hz with 6% and an availability >99.5% but requires ∼30 Up 7 A h have been...
Although the proton was discovered about 100 years ago, its spin structure still remains a mystery. Recent studies suggest that orbital angular momentum of sea quarks could significantly contribute to proton's spin. The SeaQuest experiment, which recently completed data collection, probed unpolarized light quark distributions using Drell-Yan process. Its successor, SpinQuest (E1039), will access $\bar{u}$ and $\bar{d}$ Sivers functions polarized NH$_3$ ND$_3$ targets. A non-zero asymmetry,...
Although the proton was discovered about 100 years ago, its spin structure still remains a mystery. Recent studies suggest that orbital angular momentum of sea quarks could significantly contribute to proton's spin. The SeaQuest experiment, which recently completed data collection, probed unpolarized light quark distributions using Drell-Yan process. Its successor, SpinQuest (E1039), will access $\bar{u}$ and $\bar{d}$ Sivers functions polarized NH$_3$ ND$_3$ targets. A non-zero asymmetry,...
The measurement of transverse single spin asymmetries (AN ) provides insight into the structure nucleon.Several mechanisms have been proposed that attempt to explain AN based on QCD, and additional measurements for different processes further constrain these models.Using PHENIX detector at Relativistic Heavy Ion Collider (RHIC), we study transversely polarized p+p collisions.Results from other experiments show significant in forward region, which could be due contributions both Sivers...
The Multi-cusp Cesiated Surface Conversion H- Ion Source at the Los Alamos Neutron Science Center (LANSCE) has provided beam ~14 mA, 120 Hz, and 10% D.F. for many years of neutron science research. Recently, random high current transients were discovered in arc used to ionize hydrogen LANSCE ion source, convertor convert protons ions. Most have no effect, but more severe can cripple output. Hypothesized causes are related cesiation effects, plasma instabilities, tungsten filament...
The Los Alamos Neutron Science Center (LANSCE) H− ion source (LHIS) has provided stable output for decades of LANL mission needs. While several in-house improvements have been made to its stability and lifetime, maximum beam remained the same at ~14 mA. operationally well understood, internal relationship between LHIS plasma, cesium distribution (the catalyst producing ions), produced remains a mystery, only explored indirectly with models. We will develop fast, accurate, non-invasive...
In QCD, nucleon spin comes from the sum of quark spin, gluon and orbital angular momentum, but how these different components contribute interplay among them is not yet understood. For instance, sea contribution remains largely unexplored. Measurements Sivers function for quarks will provide a probe contribution. The upcoming E1039 experiment at Fermilab measure asymmetry via Drell-Yan process using 120 GeV unpolarized proton beam directed transversely polarized ammonia target. We report on...
One of the great challenges QCD is trying to understand origin nucleon spin. Several decades experimental measurements have shown that our current understanding incomplete if only quark and gluon spin contribution considered. Over last few years it has become increasingly clear from orbital angular momentum quarks gluons be included as well. For instance, sea remains largely unexplored. Measurements accessing Sivers distribution will provide a probe contribution. The upcoming E1039...
Inclusive transverse single spin asymmetries from high energetic polarized proton collisions provide insight into the spin-momentum correlations in QCD. Originally expected to be small collinear perturbative QCD, results PHENIX and other experiments show significant forward momentum direction of over a wide range center-of-mass energies. Several mechanisms have been proposed that attempt explain these asymmetries, which include initial final state effects. In order disentangle effects,...